Semiconductor devices with plastic housing compositions are in widespread use in semiconductor electronics. On the one hand, the plastic housing composition is intended to protect and hold together the electronic components and, on the other hand, in so far as internal wirings are provided within the semiconductor device, they are intended to be electrically insulated from one another by the plastic housing composition. Filler particles are introduced into a plastic housing composition of this type and they are intended to reduce the coefficient of expansion of the plastic housing composition to an extent such that the thermal stresses between the plastic housing composition and semiconductor chips are reduced, and the filler particles are intended to increase thermal conductivity.
U.S. Pat. No. 5,011,872 discloses a plastic composition which has boron nitride as filler particles and, alternatively, also contains silicon carbide and aluminum nitride, in order to improve the thermal conductivity of the plastic housing composition and simultaneously to reduce the coefficient of thermal expansion of the plastic housing composition. U.S. Pat. No. 4,265,755 discloses a filler material which contains aluminum nitride, boron nitride or zinc oxide, having good thermal conductivity, and is intended to electrically insulate the components of the electronic semiconductor device from one another. U.S. Pat. No. 5,681,883 discloses a plastic composition for an injection molding method in which filler particles comprising boron nitride are admixed in order to reduce the thermal resistance and at the same time to reduce the coefficient of expansion of the plastic housing composition.
A common limitation to all of the previously described plastic compositions with fillers is that they have ceramic fillers which are limited in terms of their thermal conductivity and also cannot adequately decrease the coefficient of thermal expansion of the plastic housing composition even with a high degree of filler of 92% by volume.